/*
 *    This program is free software; you can redistribute it and/or modify
 *    it under the terms of the GNU General Public License as published by
 *    the Free Software Foundation; either version 2 of the License, or
 *    (at your option) any later version.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU General Public License for more details.
 *
 *    You should have received a copy of the GNU General Public License
 *    along with this program; if not, write to the Free Software
 *    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

/*
 * IteratedLovinsStemmer.java
 * Copyright (C) 2001 University of Waikato, Hamilton, New Zealand
 *
 */

package weka.core.stemmers;

import weka.core.RevisionUtils;

/**
 * <!-- globalinfo-start --> An iterated version of the Lovins stemmer. It stems
 * the word (in case it's longer than 2 characters) until it no further changes.<br/>
 * <br/>
 * For more information about the Lovins stemmer see:<br/>
 * <br/>
 * Julie Beth Lovins (1968). Development of a stemming algorithm. Mechanical
 * Translation and Computational Linguistics. 11:22-31.
 * <p/>
 * <!-- globalinfo-end -->
 * 
 * <!-- technical-bibtex-start --> BibTeX:
 * 
 * <pre>
 * &#64;article{Lovins1968,
 *    author = {Julie Beth Lovins},
 *    journal = {Mechanical Translation and Computational Linguistics},
 *    pages = {22-31},
 *    title = {Development of a stemming algorithm},
 *    volume = {11},
 *    year = {1968}
 * }
 * </pre>
 * <p/>
 * <!-- technical-bibtex-end -->
 * 
 * @author Eibe Frank (eibe at cs dot waikato dot ac dot nz)
 * @version $Revision: 1.7 $
 * @see LovinsStemmer
 */
public class IteratedLovinsStemmer extends LovinsStemmer {

	/** for serialization */
	static final long serialVersionUID = 960689687163788264L;

	/**
	 * Returns a string describing the stemmer
	 * 
	 * @return a description suitable for displaying in the
	 *         explorer/experimenter gui
	 */
	public String globalInfo() {
		return "An iterated version of the Lovins stemmer. It stems the word (in "
				+ "case it's longer than 2 characters) until it no further changes.\n\n"
				+ "For more information about the Lovins stemmer see:\n\n"
				+ getTechnicalInformation().toString();
	}

	/**
	 * Iterated stemming of the given word. Word is converted to lower case.
	 * 
	 * @param str
	 *            the word to stem
	 * @return the stemmed word
	 */
	public String stem(String str) {

		if (str.length() <= 2) {
			return str;
		}
		String stemmed = super.stem(str);
		while (!stemmed.equals(str)) {
			str = stemmed;
			stemmed = super.stem(stemmed);
		}
		return stemmed;
	}

	/**
	 * Returns the revision string.
	 * 
	 * @return the revision
	 */
	public String getRevision() {
		return RevisionUtils.extract("$Revision: 1.7 $");
	}

	/**
	 * Runs the stemmer with the given options
	 * 
	 * @param args
	 *            the options
	 */
	public static void main(String[] args) {
		try {
			Stemming.useStemmer(new IteratedLovinsStemmer(), args);
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
}
